Hair clipper



Nov;y 19, 1940.

R. KNAPP 2,222,106

HAIR GLIPPER Filed Dec. 2 8, 1936 5 Sheets-Sheet l ATTORNEYS 3 Sheets-Sheet 2 R. KNAPP HAIR CLIPPER Filed Dec. 28, 1936 Nov. 19, 1940.

INVENjOZ @Wm N BY ma',

Nov. 19, 1940. R, KNAPP 2,222,106

HAIR CLIPPER A Filed Deo. 28, 1936 3 Sheets-Sheet 5 INVENTOR ATTORNEYS Patented Nov. 19, 1940 UNITED STATES PATENT ori-lcs Application December 28, 1936, Serial No. 117,7463

10 Claims.

This invention relates to improvements in motor-driven hair-clippers. Although the clippers of my invention are capable of use for all purposes for which hair clippers are generally used,

t they are particularly adapted for clipping hair on the face, and so are of the type of clippers commonly called dry-Shavers, (a misnomer because they remove the hair by shearing and not by the shaving action of a razor blade). It has been my object to improve and simplify the construction and operation of such devices and enlarge their field of usefulness.

The hair-clippers in general use today by barbers are adapted for cutting relatively long hair but not the short hair of a one days growth of beard. Nor are they designed to produce a short clip comparable to the cut of a razor blade. On the other hand, it is practically impossible to cut long hair with the dry shavers in most common use today. Moreover these instruments are so designed that the cut hair is retained within the interior of a closed shear plate, resulting in freuuent clogging of the cutting elements. In my clipper the shear plates are so constructed that long hair can be as readily cut as short, the cut portions being left outside the plates, and an excellent dry-shave effected in any case without clogging,

Another important feature of my clipper is the mounting of the shear plates. They are so mounted in the cutter head that they cannot be loosened by vibration of the machine and yet can be easily and quickly attached and detached.

l have also devisedan improved and tool-prooi starting mechanism for the motor.

These and other improvements are illustrated in the accompanying drawings in which Figure 1 is an enlarged scale longitudinal secm tion of a clipper embodying my invention, taken along line l-l ol Figure 2; Figure 2 is a view taken along line 2-2 of Figure 1 Figure 3 is a transverse section through the cutter head and shear plates, on a still further enlarged i scale talren along line 3 3 of Figure 2; Figures and 5 are views similar to Figure 3 taken along lines Il--d and 5--5 respectively of Figure 2; Figure 6 is an elevation of the fixed shear plate; .Figure 'l is an elevation of the movable shear plate; Figures B, 9 and 10 are sections similar to Figures 3, l and 5 respectively, but showing a modified form of the shear plates with conseuuent modification in the cutter head; Figure 1l is an elevation of the fixed shear plate shown in Figures 8, 9 and 10; and Figure 12 is an elevatto lill

lill

tion of the movable shear plate shown in Figures 8, 9 and 10.

The hair clipper of my invention, like all hair clippers, comprises essentially two shear plates, one xed, and one movable, and means for re- 5 ciprocating the movable plate relatively to the fixed one. These plates are provided with thin, narrowly-spaced teeth, the teeth of the movable plate moving across the spaces between the teeth in the fixed plate and shearing hairs which have 10 entered those spaces. In the form of clipper shown in Figures 1 through 7 the iixed shear plate is designated by the reference numeral I, and the movable plate by the reference numeral 2. These plates, as shown most clearly in 15 Figures 3, 4 and 5, are bent at an angle at their outer ends and may be said to resemble in crosssection an arabic numeral l. They are detachably mounted within a slot 3 in a metal cutter head 4 mounted on the chassis of a small mom tor 5 which, through suitable connections to be described presently, reciprocates the movable plate 2 relative to the hired plate l. The housing 6 of this motor is preferably made of Bakelite or similar material and serves as a handle nu for the clipper.

I shall nrst described the structure oi? the shear plates. The lined shear plate, shown in Figures l through 7, is provided near its outer end with a plurality of line teeth l spaced apart by slots 3p u of sumcient width to receive a hair. The plate is bent through and transversely of these slots, the outer end of the plate making an angle oi approximately 60 with the major portion. The outer ends oi the teeth 'l are supported by a 35, cross bar d situated below the bottoms ot the slots 8, so as not to interfere with the passage of a hair through them. The closeness of the clip effected by any hair clipper is a function oi the thickness of the shear plate which comes into m contact with the skin. For dry Shavers, therefore, it is obviously necessary to malte this plate thinner than the hired plate of hair clippers clesigned to meet less exacting requirements. For this reason the thickness ol the teeth "l is considerably less than that of the other parts of the plate l and because oi this thinness, l have found it desirable to use the supporting bar t although in the absence oi? this necessity the bar 9 could be eliminated. The side edges oi? the plate l are 5o extended slightly above the teeth "l to form reenforcing ridges l which support the outer ends of the cross bar 9.

The outer end of the movable shear plate 2 is similarly provided with spaced teeth I2 sepa- 55 rated by slots I3, and the plate bent at an angle transversely of these teeth as in the case of plate I. As shown in Figures 3, 4 and5 the movable plate is designed to nest within the angle formed in plate I and to make shearing contact with the latter along ltwo sides of the angle. As both shear plates are bent through their respective l slots two sets of shearing edges are provided along the two sides of the angle as shown most clearly in Figures 3, 4 and 5.

I shall now describe the manner in which the two shearing plates are mounted within the cutter head 4. The fixed plate I is considerably longer than the movable plate 2 and is of uniform thickness throughout its lower extension, except that its lower edge is beveled at I4 to facilitate insertion within the slot 3. This beveled edge is provided at its mid point with a keyhole slot I5 designed to be engaged by a spring-pressed detent I6 mounted within a bore I1 in the cutter head 4, as shown most clearly in Figure 4. A compression spring I8 at the base of this bore normally urges the detent outwardly, the extent of the outward movement being limited by a stop I9 lying within a groove 20 in the detent. Not far from its inner end, the detent I6 is cut away to form a section 22 of a diameter less than the width of the mouth of the slot I5. To seat the plate I within the cutter head it is inserted within the slot 3 until the mouth of the keyhole slot I5 engages the detent I6. But as the detent is too wide to enter the mouth of this slot it becomes necessary to retract the detent until the reduced section 22 is opposite the slot, whereupon the plate may be seated. When theA plate has passed over the detent and reached the bottom of the slot, the enlarged end of the keyhole I5 is in alignment with the detent, and, being of slightly larger diameter, the spring I8 may then force the detent outward into engagement with the plate,

thus holding it against retraction. Before the,

plate can be removed it becomes necessary to retract the detent by pushing inwardly on its outwardly extending end. As illustrated in Figure 4, the detent is so designed that inward pressure exerted on the plate I would force the detent inwardly until the enlarged section of the keyhole slot I5 should register with the detent, whereupon the spring I8 would snap it into engaging position. The movable plate 2 being nested within the angle of the fixed plate I is mounted within the cutter head and demounted with the xed plate.

I shall now describe how the movable plate is held in shearing contact with the xed plate. The lower edge of the plate 2 terminates in an enlargement 23 provided at two points along its lower face with conical depressions 24. These depressions 24 are `designed to receive two springpressed pins 25 mounted within bores 26 in the cutter head 4, as shown most clearly in Figures 2 and 5. Each of these pins is provided with a conical shoulder 21 designed to be seated on a conical seat 28 when the plate 2 is removed, and is urged at all times toward that seat by means of a coil spring 29. There is a considerable clearance 3U between the shank of each pin 25 and the cutter head, so that when the shear plates are assembled, these pins are capable of the lateral displacement made necessary by the reciprocation of the movable plate, as will be explained presently. But before the plates are mounted in the cutter head, the pins 25, by virtue of the centering effected by the seats 28, as just explained, are in accurate predetermined position and cooperate with depressions 24 to position the plate 2 properly. The springs 29 exert suiiicient pressure to hold the movable plate 2 always in operative shearing contact with the fixed plate I along both sides of the angle, and compensate for wear.

I shall now describe the means for reciprocating the movable plate 2. The vmotor 5 is an A. C.-D. C. motor, which, as it forms no part of the present invention, need not be described in detail. Mounted on the rotor shaft 32 of this motor is an eccentric cam 33 lying within and contacting with the forks of a yoke 34 at one end of an arm 35 pivoted at 36 on the motor chassis. The other end of this arm beyond the pivot 36 terminates within a notch 31 in the lower face of the enlargement 23 of the movable plate 2, all of which is shown most clearly in Figures 1, 2 and 3. As the detent I6 is centered with lreference to the cutter head, it becomes necessary to off-set the plate-contacting end of the arm 35, as shown in Figure 2. By means of the mechanism just described, rotation of the rotor shaft produces a reciprocation of the plate 2 with reference to the fixed plate I.

I shall now describe'the improved motor starting mechanism of my invention. If, when the motor is plugged in the ordinary way into an available current outlet, the interrupter necessary for D. C. operation is open, the motor will not start. It therefore becomes necessary to give the rotor a turn to close the interrupter. The means heretofore used in practice to give this starting spin to the rotor has taken the form of a small gear wheel meshing with a gear on the rotor and itself projecting beyond the motor housing for engagement by the operators thumb. The objection to this starting means is that frequently the user of the clipper inadvertently places his thumb `or finger on the rotating starting wheel and unintentionally stops the motor while using the machine. My starting device avoids this diiliculty entirely. Fixed on therotor shaft 32 beyond the cam 33 is a ratchet wheel 38. Mounted along and above the chassis of the motor is a slide bar 39 terminating at its outer end in a block 40 having an upstanding flange 4I serving as a nger hold and at the other end in a claw 42 normally lying around but out of engagement with the ratchet and held in that position by means of a spring 43 in cooperation with a guide 44. Lateral movement of the bar to the left, as viewed in Figure 2, is prevented by the guide 44, but the bar is free to move to the right. To start the motor the block is pulled outward to retract the claw beyond the ratchet, the end of the claw riding over the ratchet teeth and swinging the bar laterally to the right. When the block 40 is released the spring 43 returns the slide bar 39 to its initial position, this movement bringing the end of the claw 42 into engagement with one of the teeth of the ratchet and thus giving the rotor the necessary spin.

I shall now describe the modified form of shear plates illustrated in Figures 8 through 12. In this modification the slotted end of the fixed shear plate, designated in this form as 45, is bent upwardly to form an obtuse angle of approximately 60 with the body of the plate, instead of downwardly at an acute angle of approximately 30, as in the other modication. The movable plate 46 is similarly bent. To direct hairs into the slots into the slots between the teeth, I have extended the teeth beyond the angle to form guide shoes 41. The upper end of the teeth are supdit ported by a cross bar 48 which, in this modification, closes the slots between the teeth and is, in that particular, different from the cross bar 9 in the other form.

The means for detachably mounting the plates Within the cutter head, as shown in Figure 9, are substantially identical with the means shown in Figure 4, and the means for yieldably holding the movable plate in shearing contact with the plate, illustrated in Figure 10, are substantially identical with similar means shown in Figure 5. Likewise the means for reciprocating the movable plate are substantially identical with those illustrated and described in connection with the other modiiication; with this difference, however: With the plate arrangement shown in Figures 3, 4 and 5 the movable plate is below the nxed plate and between the fixed plate and the motor. The reverse is true when the plates are arranged as. shown in Figures 8, 9 and 10. It therefore becomes necessary to provide a slot 49 in the xed plate t5 through which the end of the oscillating arm 35 may extend to engage the movable plate.

In the dry-Shavers heretofore in use the handle has been placed at right angles to the plane of the shear plate; consequently when used on thev iace the instrument must be held in a position which is awkward and unnatural, particularly to the man habituated to the ordinary safety-razor. We have seen that with the clipper of the present invention the outer and upper sections of both iorms of shear plates make angles of approximately 30 and 60 with theinner and lower sections. These in turn make an angle of approximately 40 with the longitudinal axis of the clipper handle, so that 'when the outer sections oi the shear plate are held vertical, the handle extends downward and outward at an angle of approximately 20. Thus the clipper of my invention isso constructed that in normal use the handle makes the same angle with the skin that the handle of a safety-razor makes, and so can be used by safety-razor users without unsettling old habits. This is true when using either pair of shear plates illustrated and described, and with either the clipper can be used precisely as a safety-razor is used, cutting on the downstroke with an entire reversal of the clipper when cutting on the upstroke. Unlike a safety razor, however, each form of my invention is capable oi cutting on both up and down strokes without changing the position of the clipper, as with the dry shavers in use today.

lt will be observed that the clipper of my invention is adapted for clipping hair of any length, long hair, as well as short, and this is particularly true with the shear plates shown in Figures 3, d and 5. When the clipper is moved in the direction in which the shear plate angles are pointing, any long hair encountered passes between the teeth l and is clipped at two points along its length by the angular shearing edges of the movable plate, the great bulk of the cut hair remaining on the outside face of the fixed plate. llhere is no enclosed shear plate in which hair cuttings can accumulate and clog the machinery, and all the hair cut is, in effect, always on the outside of the shear plates as with the ordinary barbers hair clipper.

IThe shear plates of my clipper can be readily attached and detached so that each member of a family may have his own set purchased for a relatively small sum, a single motor with its operating. parts, serving for all. This feature also makes the device feasible for use by barbers in those communities where the sterilization of clipper shear plates after each use is required by law...

It also makes prolonged life of the clipper possible by replacement of the relatively inexpensive shear plates after they have become too worn for eiiicient operation.

Despite the fact that my plates can be easily attached and detached. they are firmly held in position in the cutter head when the device is in use and cannot work loose as is the case with certain dry Shavers now on the market. Furthermore, the strain of holding the plates in position is borne by the metal head and not by the more fragile Bakelite motor housing.

I claim:

1. A hair clipper comprising a fixed shear plate having spaced teeth adjacent one end thereof and a single relatively flat projection at the other end, a movable shear plate likewise having spaced teeth, adjacent one end thereof and a single relatively flat projection at the other end, both plates being bent at an angle to the flat portions thereof, respectively, through and transversely of the teeth, the angle of one of said plates lying within the angle of the fixed plate with the teeth of one in shearing contact with the teeth of the' other along both sides of the angle, means comprising a clipper head having a slot for receiving the relatively hat portions of said plates with substantially the teeth only thereof projecting irom said clipper head, and means for reciprocating the movable plate relative to the fixed plate.

2. d hair clipper comprising a fixed shear plate having spaced teeth, a movable shear plate likewise having spaced teeth, both plates being bent at an obtuse angle transversely of the teeth, the angle of the movable plate lying within the angle of the fixed plate with the teeth of one in shearing contact with the lteeth oi the other, a notch ln the movable plate, a handle, means for mounting the plates on the handle, an arm pivoted on the handle beyond the iixed plate and terminating within the notch, a slot in the fixed plate through which the arm passes to reach the notch, and means for oscillating the arm to reciprocate the movable plate relative to the fixed plate.

3. A hair clipper comprising a fixed shear plate, a movable shear platea cutter head, a slot in the cutter head for receiving the shear plates, yieldable latch means for detachably holding the shear plates within the slot, resilient means in the cutter head urged in a substantially lateral direction against the shear plates normally and positively holding the shear plates within the slot and means for reciprocating the movable plate relative to the fixed plate.

4;. A hair clipper comprising a iixed shear plate, a movable shear plate, a cutter head, a slot in the cutter head for receiving the shear plates, a notch in the fixed plate, a spring-pressed detent in the cutter head operable substantially laterally with respect thereto cooperating with the notch to positively hold the plates Within the slot, said detent being manually adjustable to a position permitting detachament of said plates from said cutter head and means for reciprocating the movable plate relative to the fixed plate.

5. A hair clipper comprising a fixed shear plate, a movable shear plate, a cutter head, a slot in the cutter head for receiving the shear plates, a keyhole slot in the fixed plate, a spring-pressed detent extending across the cutter head slot in alinement with the keyhole, a reduced section in the detent capable of entering the mouth vof the keyhole slot, the body of the detent being capable of entering the enlarged end of the keyhole but not its mouth, whereby the plate may be detachably mounted within the cutter head, and means for reciprocating the movable plate relative to the ixed plate.

6. A hair clipper comprising a xed shear plate having spaced teeth, a movable shear plate likewise having spaced teeth, both plates being bent at an angle through and transversely of the teeth, the angle of the movable plate lying within the angle of the fixed plate, a cutter head, means for detachably mounting the shear plates in the cutter head, a cylindrical bore in the cutter head closed at one end, a pin in the cutter head positioned partly within the bore engaging the base of the movable plate to hold the teeth of the movable plate in yieldable shearing contact with the teeth of the fixed plate, an enlargement on the pin within said bore, an opening in the cutter head .through which the pin projects, said opening being smaller than said enlargement, a coil spring having one end on the portion of said pin inside of said enlargement and its other end seated in the closed end of said bore, and means for reciprocating the movable plate relative to the fixed plate.

'1. A hair clipper comprising a fixed shear plate, a movable shear plate, a motor having a rotor for reciprocating the cutter plate relative to the shear plate, a housing for the motor, a ratchet wheel on the rotor shaft, an elongated bar slidably mounted for longitudinal movement thereo f within the motor housing, a guide for the inside end of the bar greater in width than the bar to permit a limited lateral movement thereof in one direction, a claw at said inside end of the bar normally lying adjacent to but out of contact with the ratchet, yieldable means for urging said claw against the wheel throughout a portion of its movement and a finger hold on the other end of the bar lying outside the motor housing whereby the bar can be moved in an axial direction to bring the claw into engagement with the ratchet to turn the rotor and start the motor.

8. A hair clipper comprising a clipper head having a slot therein extending laterally across the head, a shearing member comprising a relatively fiat fixed plate of uniform thickness having spaced teeth at the outer end, a second shearing member'comprising a relatively flat movable plate of uniform thickness having spaced teeth at the outer end, said second plate being substantially coincident throughout its outer portion with the rst shear plate, both said plates at the outer portions having the form of an open angle including superimposed coincident angular teeth wherein the teeth on both plates are exposed and means for reciprocating the movable plate relative to the fixed plate.

9. A hair clipper comprising a fixed shear plate having exposed teeth adjacent one end thereof and a single relatively flat projection adjacent the other end, a movable shear plate likewise having spaced teeth adjacent one end and a single projection adjacent the other end, both plates being in face to face contact and bent through and transverselyv oi their respective teeth at coinciding acute angles relative to said flat projection, a clipper head having a transverse slot therein, said iiat projection of the xed shear plate being positioned in said slot with the other end projecting therefrom, resilient means in the slot urged against the movable plate projection having a line of action parallel to said flat projection whereby both sides of the acute angle of the movable plate are urged into shearing contact with the xed plate and means for reciprocating the movable plate relative to the fixed plate.

10. In a hair clipper comprising a iixed shear plate, a movable shear plate, a motor having a rotor for reciprocating the movable shear plate relative to the ixed shear plate and a casing for the shear plates and the motor, the combination of a toothed wheel on the rotor shaft and a rigid elongated bar comprising a single member mounted with its axis substantially parallel to the axis of said casing, a plurality of spaced supports in the casing along the axis of said bar, one adjacent the end of the casing and the other within the casing adjacent the wheel, said bar having a sliding movement endwise relative to said supports and the casing, said support adjacent the wheel having a relatively loose connection with the bar permitting a limited lateral movement for the inner end, said bar having a claw at the inner end engaging the toothed wheel when the inner end is shifted in one lateral direction and having the other end extending be yond the end of the motor casing for imparting a sliding movement in a substantially axial direction to the bar in order'to turn the rotor and start the motor.

RAYMOND KNAPP. 

